Fleeming Jenkin (1833–1885) was the first person in Britain to draw supply and demand curves, discussing them as mathematical functions and employing them to study economic problems. A celebrated engineer, he made remarkable contributions to economics, that attracted little attention in his time. This article goes through Jenkin's thought, emphasizing his analysis of the three laws of supply and demand, and its application to the labour market and die taxes, mat produced the independent discovery of die notion of consumer and producer surplus. The article holds that a reason why Jenkin lacked die acknowledgement he deserved lay in the hostile attitude towards him by Jevons and Marshall, who undervalued his contributions and insisted that they had anticipated Jenkin. The article concludes that this claim is unfounded.